US spot Bitcoin ETFs attracted $986.9 million in net inflows for the week ending September 5, capping off a three-week streak that has funneled $3.8 billion into these products. Early 2026 was rough for Bitcoin ETF flows, with year-to-date net figures still sitting at approximately negative $1 billion. Three consecutive weeks of heavy buying haven’t erased that deficit, but they’ve dramatically narrowed it.
Thursday was the main event
Daily inflows during the week were anything but evenly distributed. Thursday alone accounted for roughly $731 million in net new capital, the largest single-day haul since January 14. Friday cooled off to $174.6 million. BlackRock’s iShares Bitcoin Trust (IBIT) was responsible for $117.4 million of that total, while Fidelity’s Wise Origin Bitcoin Fund (FBTC) contributed $57.2 million.
Total assets under management across all US spot Bitcoin ETFs stood at $101.3 billion as of the latest data, after briefly touching $103.3 billion during the week. Since their collective launch in January 2024, these funds have accumulated $55.6 billion in cumulative net inflows.
Bitcoin holds steady while altcoin ETFs bleed
Bitcoin’s price during the week hovered near $80K, dipping briefly below $79K before recovering to roughly $79,700. Spot Ether ETF inflows dropped 74% week-over-week, while XRP ETF products saw an 83% decline.
August 2026 delivered $3.5 billion in total Bitcoin ETF inflows, marking the strongest month since September 2025.
Digging out of a hole
That the year-to-date figure still sits around negative $1 billion, even after $3.8 billion in three-week inflows, illustrates just how severe the earlier exodus was.
The $101.3 billion in combined AUM across all spot Bitcoin ETFs represents a significant chunk of Bitcoin’s total market capitalization. At current prices near $80K, Bitcoin’s fully diluted market cap sits in the neighborhood of $1.6 trillion, meaning these ETFs collectively hold somewhere around 6% of all Bitcoin that will ever exist.